The present invention relates to an image forming apparatus, such as a copying machine, for obtaining a copy image of a document by electronic sorting or memory editing copying.
Conventionally, document inputting control of image forming apparatus are adopted following methods for determining whether or not the document is the last one.
(1) When the automatic document feeder (ADF) is in use
Each time the document feeding operation finishes, presence of a document on the ADF is detected by an optical sensor. Since all documents are to be placed on the ADF at the same time as the basic premise except a special mode, if no document is placed on the ADF at the time of starting scanning after a document feeding operation, the document to be scanned is determined to be the last one.
(2) When the ADF is not in use
Without the ADF for successive automatic paper feeding, the criterion of determining the presence of the next document depends solely upon detecting whether or not the user sets a document and depresses the copy key. However, by having the absence of the user's depressing the copy key as the criterion of no waiting document, whether or not the copy key has not been operated in a certain time needs to be detected in order to make judgment that the copy key has not been depressed. Therefore, a certain time is required for making the judgment of no waiting document.
In the case of the above-mentioned (1) the automatic document feeder (ADF) is in use, since the absence of the document on the ADF after inputting a document is judged that the preceding document is the last one, when a 4 in 1 function is used, by setting a document sheet one by one, a reduced copy of a quarter size is outputted each time a document is set.
In the case of (2) the automatic document feeder (ADF) is not in use, since a certain time is required for the judgment of no waiting document, it leads to a problem of deteriorating operativity.